1. Field of the Invention
This invention relates to a new and improved apparatus and method for washing bottles. More particularly, the invention relates to washing bottles returned to a bottling works for refilling wherein while traversing a main washing station, a jet of water directed to wash the inside of the inverted bottle tends to overcome the weight of the bottle and move the bottle off its carrier. In accordance with the present invention a counterbalancing jet of water is directed from the top toward the bottom of the inverted bottle to maintain the bottle on the conveyor.
2. Description of Related Art
Large containers such as 6 gallon, 5 gallon or 3 gallon and metric equivalent water bottles, preparatory to filling are washed, sanitized and rinsed. At multiple stations, the exteriors of the containers are sprayed with warmed cleaning solution while a pressure jet of the same solution is directed through the open neck of the inverted container into the interior. With increasing lighter weights of containers, including the shift from glass to plastic and to smaller containers, there has been a corresponding shift to lower impact pressures and flow rate, to prevent containers from being lifted off the conveyor. Although the lower impact and flow result in a reduced likelihood that containers will be lifted off the conveyor, they also reduce the effectiveness of the washing. Additionally, new containers with complex features such as handles are being introduced to the market, which make the current low impact and flow less effective. Mechanical clamps of various types have been unreliable and costly in solving the problem because of wide variations in the size, shoulder profile, neck profile and height of the containers.
The present invention differs from prior apparatus and methods for retaining the containers on the conveyor by directing a downward fluid on the inverted bottom of the container which counterbalances the upward force of the upward jet which is directed through the open neck of the container.
Although this invention may be used for other purposes, the following description will be limited to use in cleaning bottles. Preparatory to filling, returned empty bottles are passed through a washing process consisting of several stages. The apparatus involves use of a conveyor which is moved, preferably intermittently, through a loading stage where the bottles are loaded onto a conveyor either manually or mechanically. In the main wash stage, wash detergent solution heated by electric heaters or steam coils or by an external solution heater is pumped through nozzles. Multiple nozzles direct the spray outside each bottle. At each stage there is an upwardly directed jet of solution which passes through the neck of the bottle and cleans the interior. It has been found that the combination of high impact and flow rate creates a force which tends to overcome the weight of the bottle, causing it to lift off the conveyor. There are usually several wash stages within the main wash station.
At the next station a recirculated rinse is directed within the bottle and on the outsides thereof. Typically, the pressure at the rinse stage is not as great as the pressure at the main wash stage and hence a hold-down nozzle may not be necessary at the rinse stage. From the rinse stage the bottles pass to a sanitizing stage where ozonated water, chlorinated water or commercial sanitizing agents are used to sanitize the inside of the bottle. Following the sanitizing stage there is a final rinse stage where clean water is used inside the bottle to remove all residual materials, leaving the bottle completely clean and sanitized and ready for filling.
The present invention is an improvement over prior washing systems in that at the main wash stage a jet of fluid is directed downwardly against the inverted bottom of each bottle to counterbalance the upward force of the jet inserting water into the interior of the bottle and thereby preventing the bottle from being lifted off the holder. A similar downward jet may be used at other stages, as may be required.